Spraying device incorporating safety features have already been suggested. However, most attempts to provide safety features have centered upon the use of protective insulation, neutralization or the use of a protective ground.
With the spraying device of the invention the risk of injury upon unintentional or accidental release of the sprayer is reduced in that discharge of the sprayed agent is halted. The spraying device of the invention requires no mechanical cut-out means in the hand tool the operation of which could be adversely affected by abrasive or corrosive agents, high temperatures and high pressures. For the control of the pressure and heat generator via the hand tool, low voltages and little power may be used. Thus, the cost of protective insulation, neutralization or a protective ground in prior art devices is entirely eliminated. Moreover, an additional conductor in the high-pressure hose for transmitting the control voltage is not required. With the spraying device disclosed and claimed herein the pressure and heat generator can be switched off safely and quickly by preventing pressure peaks in those components carrying or storing the agents.
It is particularly an object of the present invention to provide a spraying device of the kind as herein described which cannot be actuated by coupled interference voltages.